From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastien Guiriec Subject: Re: [PATCH v2 1/4] ARM: dts: omap5: Update GPIO with address space and interrupts Date: Tue, 23 Oct 2012 18:15:24 +0200 Message-ID: <5086C29C.5000209@ti.com> References: <1350981432-6750-1-git-send-email-s-guiriec@ti.com> <1350981432-6750-2-git-send-email-s-guiriec@ti.com> <5086AE8E.60106@ti.com> <5086B316.6000001@ti.com> <5086BECA.9070502@ti.com> <5086C0C3.1060305@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5086C0C3.1060305@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Benoit Cousson Cc: Jon Hunter , Tony Lindgren , devicetree-discuss@lists.ozlabs.org, linux-omap@vger.kernel.org, Santosh Shilimkar , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org Hi Benoit and John, On 10/23/2012 06:07 PM, Benoit Cousson wrote: > On 10/23/2012 05:59 PM, Jon Hunter wrote: >> >> On 10/23/2012 10:09 AM, Benoit Cousson wrote: >>> On 10/23/2012 04:49 PM, Jon Hunter wrote: >>>> Hi Seb, >>>> >>>> On 10/23/2012 03:37 AM, Sebastien Guiriec wrote: >>>>> Add base address and interrupt line inside Device Tree data for >>>>> OMAP5 >>>>> >>>>> Signed-off-by: Sebastien Guiriec >>>>> --- >>>>> arch/arm/boot/dts/omap5.dtsi | 16 ++++++++++++++++ >>>>> 1 file changed, 16 insertions(+) >>>>> >>>>> diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi >>>>> index 42c78be..9e39f9f 100644 >>>>> --- a/arch/arm/boot/dts/omap5.dtsi >>>>> +++ b/arch/arm/boot/dts/omap5.dtsi >>>>> @@ -104,6 +104,8 @@ >>>>> >>>>> gpio1: gpio@4ae10000 { >>>>> compatible = "ti,omap4-gpio"; >>>>> + reg = <0x4ae10000 0x200>; >>>>> + interrupts = <0 29 0x4>; >>>>> ti,hwmods = "gpio1"; >>>>> gpio-controller; >>>>> #gpio-cells = <2>; >>>> >>>> I am wondering if we should add the "interrupt-parent" property to add >>>> nodes in the device-tree source. I know that today the interrupt-parent >>>> is being defined globally, but when device-tree maps an interrupt for a >>>> device it searches for the interrupt-parent starting the current device >>>> node. >>>> >>>> So in other words, for gpio1 it will search the gpio1 binding for >>>> "interrupt-parent" and if not found move up a level and search again. It >>>> will keep doing this until it finds the "interrupt-parent". >>>> >>>> Therefore, I believe it will improve search time and hence, boot time if >>>> we have interrupt-parent defined in each node. >>> >>> Mmm, I'm not that sure. it will increase the size of the blob, so >>> increase the time to load it and then to parse it. Where in the current >>> case, it is just going up to the parent node using the already >>> un-flatten tree in memory and thus that should not take that much time. >> >> Yes it will definitely increase the size, so that could slow things down. >> >>> That being said, it might be interesting to benchmark that to see what >>> is the real impact. >> >> Right, I wonder what the key functions are we need to benchmark to get >> an overall feel for what is best? Right now I am seeing some people add >> the interrupt-parent for device nodes and others not. Ideally we should >> be consistent, but at the same time it is probably something that we can >> easily sort out later. So not a big deal either way. > > For consistency, I'd rather not add it at all for the moment. > Later, when we will only support DT boot, people will start complaining > about the boot time increase and then we will start optimizing a little > bit :-) I just do it like that to be consistent with what is inside OMAP4 dtsi for those IPs (GPIO/UART/MMC/I2C). Now after checking Peter already add the interrupt-parent for all audio IPs (OMAP3/4/5). But here we need also interrupts name. So here we should try to be consistent. So I can send back the series for OMAP5 and update the OMAP4 with interrupts-parent = <&gic> As of today we are not consistent. > > Regards, > Benoit > >